This invention teaches concepts for the design of ski boots that amplify the edging action of the ski. In modern skiing techniques, a dominant aspect of ski control is "edging," which is the ability to control the lateral angle of the ski with respect to the snow surface. Precise edging control is especially valuable in a forward lean position, when the skier is pressing forward against the upper portion of his boots.
Ski boots of early design were relatively flexible and the skier had to exert strong muscular restraints on lateral flexibility of the ankle to control edging action. Most of the ski boots currently available are made of stiff materials and have relatively little lateral flexibility; with these, edging ability of the skier is greatly facilitated.
Ski boot designers strive to transfer lateral angulation of the lower leg to the ski. Under ideal conditions where there is no lost motion between leg and boot, the edging angle of the ski equals the lateral inclination of the vertical axis of the skier's lower leg. However, lost motion is always encountered, caused for example by compression of boot padding and clothing and by compression of flesh and muscle under boot forces.
The lever-type ski boot of U.S. Pat. No. 3,747,235 exhibited numerous assets not related to edging, but in addition, contributed to further reduction of lost lateral motion through increased height of the leg-boot connection. The contact forces between leg and boot-top were thereby reduced, thus reducing compression of contact materials; and the angular displacement of the ski corresponding to any relative motion between leg and boot-top was also attenuated by virtue of the high position of the leg-boot connection.
In large measure, these improvements brought about the simplifications in skiing techniques employed today. Whereas prior techniques used greatly exaggerated angulation of the lower body to edge the skis, a more modest angulation is now used. The center of gravity of body weight is kept directly above the skis without severe body contortions and the more natural stance leads to easier, quicker body reactions.
The present invention teaches means for further enhancement of edging action. Even less angulation of the lower body is required for a given ski angulation, the body assumes an even more natural stance and body motions become still easier and quicker.